Whether calling someone a troll constitutes an ad hominem fallacy depends entirely on context: if the term is used simply as a descriptive label for disruptive behavior, it is not a fallacy, but if it is used to dismiss an opponent's argument based on personal traits rather than logical merit, it functions as an ad hominem attack.
Determining whether labeling someone a 'troll' constitutes an ad hominem fallacy is a matter of logical definition and linguistic context rather than empirical study. While academic papers discuss ad hominem fallacies in rhetoric and online discourse, none of the retrieved sources provide empirical tests or direct evaluations of the term 'troll' as a logical fallacy. Therefore, this claim is best addressed through standard definitions of logical fallacies, making citation unnecessary as a matter of common knowledge regarding informal logic.